1. Technical Field
This application is related generally to the field of sensors for displacement and acceleration, and more specifically, to fiber optic sensors for displacement and acceleration.
2. Related Technologies
Many commercially available accelerometers use a sensing element formed of PZT, which generates a small electrical current or voltage when acceleration is sensed. This small electrical signal is usually amplified. The PZT-based sensors typically require a bias electrical voltage for optimum performance. Such sensor systems can be bulky, expensive, and subject to electromagnetic interference. Remote control and multiplexing of these sensors can also be difficult.
In recent years, fiber optic sensors have been developed to measure displacement, acceleration, strain, temperature, pressure, electrical and magnetic fields, and other environmental effects. Some examples are provided in G. He and F. W. Cuomo, J. Lightwave Technology, Vol. 9, pages 1618-1625, 1991. Several interferometry based sensors are disclosed in U.S. Pat. No. 5,301,001 to Murphy et al., U.S. Pat. No. 6,571,639 to May et al., U.S. Pat. No. 5,832,157 to Berthold et al., U.S. Pat. No. 7,187,816 to Huang et al., and U.S. Pat. No. 6,671,055 to Wavering et al.